Interior Lights Wont Light

[DonovanM]

My '05 just began exhibiting a problem that I can't find in the manuals or in my searches on TDR... My interior lights (reading lamps) won't light unless I turn the brightness riostat up to the "on" position (one click below the "Cargo Lamp" position). When there, I can turn the lights on & off (they used to remain on in that setting and not turn off) but it keeps the dash lights on the brightest setting. If the switch is in the normal driving mode, the lamps won't light at all.



The really strange thing is that my truck was parked for a week while my family and I were on a trip; when we got back to the airport last night the interior lights operated normally when we first got in the truck, but then after about 10-15 seconds they went back to no longer working.



Does anyone know what's causing this, or what I can do to fix it????

 

[rbattelle]

Oh man, that's going to be a hard one to diagnose.

I think the first thing I'd try is unplugging both batteries for an hour or so. That should force all the vehicle computers to reboot. Maybe one of them is locked up or something.

Do you have cab clearance lights? If so, pull the overhead out and check for moisture in it from a leaking cab light. Check all the connections as well.

Ryan

 

[DonovanM]

I don't have the cab clearance lights. I'll try disconnecting both batteries tonight and see if that fixes it.

 

[ENafziger]

I don't know if it would help your particular situation, but there is a TSB out that deals with dome lights turning off too soon.



Tsb # 08 026 06 Flash ccn for inacurate o/head temp and or dome light turning off too soon



Maybe this would be an option to try if disconnecting the batteries doesn't work. --Eric

 

[DonovanM]

Update...

Disconnecting the batteries didn't work. I have an appointment to take it to the local dealer's service center next week. Will let you know what they say. Thanks for the input... this one has me completely stumped!!!

 

[jelag]

I have an F550 that had this problem..... has a PCM that controls all the lights, door locks, windows etc... . Dealer had it for 2 days, could not fix it and returned it to us..... we SAW it all apart... . came back with no bill to us because they couldn't fix it... . the same day the driver closed the door and the next time he opened it they worked and have worked every since... . 3 years now...

We decided it was a bad connection... . I suggest if your out of warranty... . you pull the connections apart and push them back together with your fingers crossed.....

I know this is not what your looking for but its what happened to us... .

 

[Allnew2Me]

This may be a long shot but check the IOD fuse to see if it is blown. It is usually in a yellow holder in the interior fuse block. IOD stands for ignition off draw, and it is the fuse that is pulled for shipment to make sure the batteries don't drain while in transit. If it is blown, you may not have the interior lights until you activate them with the headlight control, which supplies power independantly. This is just a guess but worth a try.

 

[DonovanM]

They found the problem... I'm better off in the dark!!!

After two visits to the dealer, they say they've found the problem. I'm not sure how much stock I should place in their diagnosis, though. The first time they "fixed" it, I picked it up to discover that all the technician did was turn the dash switch to the "always on" position and the lights were able to be switched on/off. No kidding!!! I showed that to the service manager when I dropped the truck off.



This time they called me to say they identified the problem as the lighting control module that is on the backside of the instrument cluster. They say that mine has gone bad, but it can't be replaced without replacing the entire dash cluster. And here's the real beautiful thing about it... they have to custom order a new dash directly from Dodge so it will arrive with the new odometer programed to match my current odometer reading and the onboard computer. Total cost: $1200 non-warrantee -- I passed!



What I REAALLLY don't understand, though is why the dash odometer has to be "programmed" at all. The service manager tried to explain that the consumer can't change the computer's information, but they CAN replace the dash odometer with an aftermarket one and hide mileage, so the dash odometer reading has to be programmed by Dodge to match the computer's recorded mileage or it will appear I was involved in odometer tampering. I countered with the point that if the onboard computer is the final, most accurate source of mileage information; and if they go by the computer's reading if it and the dash odometer differ -- then why not just have the dash odometer display the computer's mileage value instead of being "programmed" separately???? Or, why not at least give the tech the ability to download the computer's mileage to the odometer??? He said he couldn't answer that question... but I suspect it's to ensure that Dodge protects a lucrative market in replacement parts!!!



I guess I have to remain in the dark! Does anyone else know of a way to replace this part and ensure that my odometer reading is accurate?

 

[rbattelle]

Ouch, sorry to hear that.

At this point, I'd consider re-wiring the electrical system for those lights with your own design. Completely bypass the factory system. We're only talking about 3 lights here, so it's not too involved.

Or, learn to live with it.

Ryan